In agreement with SCHLENK (I78) "nucleotide" is here taken to mean a phosphoric ester of an N-glycoside of a heterocyclic base. Although they fall outside the scope of this definition, phosphorylated derivatives of riboflavin are added in recognition of their close relation to the main body of nucleotides. A complete review of even the organic chemistry of nucleotides and their derivatives would now form a substantial monograph. The smaller and less characteristic fragments of the nucleotides, namely the hetero cyclic bases, the component sugars and the derived sugar phosphates, are therefore...

The properties of proteins are determined not only by the sequence of amino-acid residues in the polypeptide chains, but also by the con figuration of the chains-the way in which the chains are coiled or folded. It is probable that denaturation, the loss of some of the specific properties of a native protein, may in many cases be the result simply of a change in configuration of the polypeptide chains, without any change whatever in the sequence of amino-acid residues. During the past few years great progress has been made in the attack on the determination of the sequence of amino-acid...